Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 010324
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1124 PM EDT FRI JUL 31 2015

.SYNOPSIS...
A WEAK FRONT WILL WAVE ACROSS THE COASTAL CAROLINAS THIS
WEEKEND...PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS NEAR THE
COAST SATURDAY. THE FRONT SHOULD DISSIPATE SUNDAY NIGHT. BERMUDA
HIGH PRESSURE WELL OFFSHORE WILL BUILD WESTWARD NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1030 PM FRIDAY...BASICALLY THE FORECAST AREA FROM THE I-95
CORRIDOR TO THE COAST WILL BE UNDER THE GUN THE REMAINDER OF THIS
EVENING FOR THE CONTINUED THREAT FOR CONVECTION.
OVERALL...CONVECTION IS ON THE DECLINE OVER LAND AREAS. THE
STALLED COOL FRONT JUST INLAND FROM THE COAST WILL CONTINUE TO
PROVIDE THE NECESSARY SFC CONVERGENCE FOR POSSIBLE OVERNIGHT
CONVECTION DEPENDING HOW MUCH JUICE...AVAILABLE CAPE REMAINS.
AFTER MIDNIGHT AND CONTINUING THRU THE SAT PRE-DAWN HRS...WILL
LIKELY OBSERVE NOCTURNALLY DRIVEN CONVECTION OVER THE ADJACENT
ATLANTIC WATERS TAKE CHARGE. AND FOR THAT REASON...HAVE KEPT
ATLEAST A CHANCE POP FOR THE IMMEDIATE COASTAL COUNTIES AFTER
MIDNIGHT IN CASE OF CHAOTIC MOVEMENT DIRECTIONS BY INDIVIDUAL
CELLS. AS YOU TRAVEL INLAND AFTER MIDNIGHT...POPS WILL LOWER TO
NO CHANCE BY THE TIME YOU REACH THE I-95 CORRIDOR. FOR TONIGHTS
LOWS BASED ON PCPN CHANCES AND CLOUD COVERAGE...A FEW TWEAKS
UPWARDS APPLIED ALONG THE IMMEDIATE COAST...AND DOWNWARDS WEST OF
THE I-95 CORRIDOR. THIS SAME TWEAKING METHOD ALSO APPLIED TO THE
OVERNIGHT HOURLY DEWPOINTS.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...BY MY COUNT THIS IS THE FOURTH FRONT TO
MAKE ITS WAY INTO COASTAL NORTH AND SOUTH CAROLINA THIS JULY.
WHILE PROBABLY NOT A RECORD IT CERTAINLY SEEMS UNUSUAL. THE FRONT
WILL OSCILLATE BACK AND FORTH ACROSS THE AREA THIS
WEEKEND...DRIVEN INLAND BY THE SEABREEZE AND PUSHED BACK TOWARD
THE COAST BY THE LATE NIGHT LANDBREEZE. THE SOUTHERN PERIPHERY OF
AN UPPER LEVEL TROUGH EXTENDING SOUTHWARD FROM HUDSON BAY WILL
POKE DOWN INTO THE MID- ATLANTIC STATES...PUNCHING A HOLE THE 500
MB RIDGE.

DEEP MOISTURE WILL LINGER ALONG THE COAST SATURDAY. THIS SHOULD
GIVE RISE TO GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS DURING THE
AFTERNOON FOR LOCATIONS WITHIN 40-50 MILES OF THE COAST...VERY
NEAR THE LOCATION OF THE STALLED FRONT AND POTENTIAL SEABREEZE
ZONE. WESTERLY MID-LEVEL WINDS WILL TEND TO PUSH STORMS EASTWARD
TOWARD THE BEACHES. FARTHER INLAND FOR THE I-95 CORRIDOR DRIER
AIR MIXED DOWN INTO THE DEEP DAYTIME BOUNDARY LAYER SHOULD LEAD TO
CONVECTIVE CAPPING AND VERY LITTLE (IF ANY) CONVECTION. HIGHS MID
90S INLAND TO UPPER 80S COAST.

FOR SUNDAY THE FRONT WILL STILL BE LINGERING ACROSS THE AREA...
HOWEVER THE MID-LEVELS ARE QUITE A BIT DRIER. THIS SHOULD LEAD TO
EVEN LESS COVERAGE OF STORMS...EVEN ALONG THE COAST WHERE 850-700
MB LAYER RELATIVE HUMIDITY WILL FALL BELOW 50 PERCENT. HIGHS
AGAIN MID 90S INLAND TO AROUND 90 AT THE COAST.

IN TERMS OF MODEL PREFERENCE...THE 12Z GFS APPEARS BETTER
TEMPERATURE AND MOISTURE-WISE THAN THE NAM AND HAS FEWER
SPURIOUS CONVECTIVE BLOWUPS...PARTICULARLY GIVEN THE LACK OF
UPPER DISTURBANCES IN THE 500 MB FLOW.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...SURFACE AND UPPER TROUGHINESS IN PLACE ON
MONDAY THOUGH MODELS LOOK A BIT QUICKER IN SHUNTING THE DEEPEST
MOISTURE OFF THE COAST. HAVE PRESERVED THE INLAND/COASTAL GRADIENT
BUT TWEAKED POPS DOWN SLIGHTLY. THE UPPER LEVEL TROUGH ALSO LOOKS
TO LIFT OUT A BIT FASTER ON TUESDAY SO RAINFALL MAY BE EVEN HARDER
TO COME BY AND JUST ISOLATED POPS AREA-WIDE. WEDNESDAY ALSO LOOKS
FAIRLY QUIET WITH ANY ENERGY IMPINGING UPON US FROM THE WEST TO
OCCUR LATE IN THE DAY OR AT NIGHT. THE CAROLINAS WILL THEN END UP
IN A REGIME OF INCREASING FLOW ALOFT WITH EMBEDDED IMPULSES THAT
TEND TO STRENGTHEN WITH TIME. RAIN CHANCES SHOULD BE ON THE RISE
THOUGH DEEP LAYER MOISTURE MAY BE HINDERED BY THE WEST-
NORTHWESTERLY MID LEVEL FLOW. DEEPER MOISTURE IN A SOUTHWESTERLY
FLOW ALOFT MAY BE RELEGATED FOR JUST AFTER THE LONG TERM. THE
MIDWEEK DAYS WHEREIN A WEAK RIDGE BUILDS ALOFT SHOULD FEATURE SOME
HEAT BUT SEEMINGLY NOT THE VERY HOT READINGS FOUND IN THE MEX MOS.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...A COLD FRONT WAS LOCATED JUST ACROSS THE COASTAL
COUNTIES OF NC/SC AND HAS INTERACTED WITH THE SEA BREEZE FRONT TO
TRIGGER CONVECTION. SCATTERED SHOWERS AND THUNDERSTORMS HAVE
AFFECTED KILM MAINLY WITH SOME VCTS AROUND KCRE. ACTIVITY STARTING
TO WIND DOWN ACROSS NC AND INCREASING ACROSS SC...ESPECIALLY WELL
SOUTH OF KMYR. WILL CARRY SHWRS AND TS AROUND THE COASTAL
TERMINALS FOR THE NEXT COUPLE OF HOURS WINDING DOWN AFTER 03Z.
MVFR CONDITIONS IN FOG BEING FORECASTED FOR COASTAL TERMINALS AND
VFR FOR INLAND TERMINALS WELL BEHIND THE FRONT WITH DRIER AIRMASS
ACROSS KLBT AND KFLO. FRONT HANGS OFF THE COAST FOR SATURDAY AND
CAN SEE MORE SCATTERED SHOWER AND TS ACTIVITY AS NUMEROUS
BOUNDARIES AND MOISTURE POOLING ALONG THIS REGION WILL HELP FIRE A
UP ACTIVITY ON SATURDAY. MVFR ACROSS THE COASTAL TERMINALS FOR
SATURDAY WITH VFR CONDITIONS ACROSS THE THE INLAND TERMINALS.

EXTENDED OUTLOOK...PREDOMINANTLY VFR THROUGH THE PERIOD WITH A
CHANCE AFTERNOON SHRA/TSRA THROUGH MONDAY.

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM FRIDAY...THE OVERALL SYNOPTIC SW WIND REGIME OVER
THE LOCAL WATERS HAS BEEN INFECTED BY OUTFLOWS FROM THE ONGOING
CONVECTION NEAR SHORE. EXPECT THIS TO CONTINUE THE REMAINDER OF
THIS EVENING AND ESPECIALLY OVERNIGHT AS CONVECTION FURTHER
FLARES UP ACROSS THE AREA AND OFFSHORE WATERS. THIS DUE TO A
MEANDERING FRONTAL BOUNDARY POSITIONED JUST INLAND FROM THE COAST.
OVERALL...STILL LOOKING AT SW WINDS 10 TO 15 KT...WITH FEW GUSTS
UP TO 20 KT ESPECIALLY FROM 10-20 NM OUT. SIGNIFICANT SEAS WILL
RANGE FROM 2 TO 4 FT...WITH 4 FOOTERS PRIMARILY OCCURRING IN THE
VICINITY OF CAPE FEAR AND SOUTHWARD. WIND DRIVEN WAVES AT 4 TO 5
SECOND PERIODS WILL MAINLY DOMINATE...BUT A SLOWLY BUILDING 1 TO 3
FOOT SOUTHEAST PSEUDO GROUND SWELL AT 8 TO 9 SECOND PERIODS WILL
OCCUR TOWARDS DAYBREAK SAT.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...A STALLED FRONT WILL WAVE BACK AND FORTH
ACROSS COASTAL NORTH AND SOUTH CAROLINA THIS WEEKEND...PUSHED
INLAND BY THE SEABREEZE CIRCULATION AND PULLED BACK DOWN TO THE
BEACHES BY THE LATE-NIGHT LANDBREEZE. IF IT WASN`T FOR THIS FRONT
BERMUDA HIGH PRESSURE WELL OFFSHORE WOULD PROVIDE A STEADY SOUTH-
SOUTHWESTERLY WIND ACROSS THE AREA. LIGHT WESTERLY WINDS SATURDAY
MORNING WILL TURN BACK TO THE SOUTH DURING THE AFTERNOON AS THE
SEABREEZE/FRONT MOVES INLAND. WINDS LATE SATURDAY NIGHT WILL AGAIN
TURN OFFSHORE...WITH WINDS SHIFTING BACK TO THE SOUTH AGAIN SUNDAY
AFTERNOON.

IN ADDITION TO LOCAL WIND WAVES THERE WILL BE AN 11-SECOND
SOUTHEAST SWELL DEVELOPING THIS WEEKEND. THE COMBINATION OF THESE
VARIOUS WAVE SETS WILL LEAD TO 2-4 FOOT SEAS THIS WEEKEND...LOWEST
ALONG THE COAST DURING THE MORNING HOURS. THERE IS SOME POTENTIAL
OF 5-FOOTERS SHOWING UP DURING BOTH SATURDAY AND SUNDAY EVENINGS
OUT BEYOND 15 MILES FROM SHORE NEAR CAPE FEAR.

LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...CONDITIONS WILL BE FAIRLY UNCHANGING
THROUGH THE PERIOD WITH SOUTHWESTERLY WINDS IN THE 10-15KT RANGE
EXPECTED THROUGHOUT. BERMUDA HIGH PRESSURE AND A PIEDMONT TROUGH
WILL BE DRIVING THESE WINDS. A STRENGTHENING OF THE LATTER COULD
ADD A FEW KNOTS OF WIND VERY LATE IN THE PERIOD. SEAS WILL AVERAGE
3 TO 4 FT THROUGHOUT.

&&

.TIDES/COASTAL FLOODING...
AS OF 800 PM FRIDAY...MINOR COASTAL FLOODING IS POSSIBLE DURING
THE NIGHT-TIME HIGH TIDE OVER THE NEXT FEW DAYS. THESE HIGHER
THAN NORMAL TIDES ARE THE RESULT OF THE PERIGEAN SPRING TIDE AND
A FULL MOON WHICH OCCURS TODAY. DEPARTURES OF PLUS 1/2 TO 1 FOOT
WILL BE ENOUGH TO PRODUCE A BRIEF PERIOD OF MINOR COASTAL
FLOODING. THE RISK IS HIGHEST FOR PORTIONS OF THE LOWER CAPE FEAR
RIVER TO INCLUDE DOWNTOWN WILMINGTON...WITH A LIKELY PROBABILITY.
HOWEVER...DURING THIS CYCLE...EVEN THE BEACHES WILL HAVE A SMALL
RISK TO ACHIEVE MINOR COASTAL FLOODING.

HIGH TIDE THIS EVENING WAS ABOUT 800 PM ACROSS THE AREA BEACHES.
TIDE GAGE READINGS FOR THE BEACHES WERE CONSISTENTLY ABOUT 1/2
FOOT BELOW MINOR/SHALLOW FLOODING THRESHOLDS. HIGH TIDE FOR THE
CAPE FEAR RIVER IN DOWNTOWN WILMINGTON WAS AROUND 1030 PM...AND
ITS READING PEAKED AT 5.64 FT MLLW...ABOVE THE MINOR/SHALLOW
FLOODING THRESHOLD OF 5.50 FT MLLW. THE COASTAL FLOOD ADVISORY
HAS BEEN ALLOWED TO EXPIRE AT 1100 PM.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 11 PM EDT THIS EVENING FOR NCZ107.
  ...HIGH RIP CURRENT RISK IN EFFECT FROM 7 AM EDT SATURDAY
     MORNING THROUGH 8 PM EDT SATURDAY EVENING FOR NCZ110.
MARINE...NONE.

&&

$$
SYNOPSIS...TRA
NEAR TERM...DCH
SHORT TERM...TRA
LONG TERM...MBB
AVIATION...MAC
TIDES/COASTAL FLOODING...DCH



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